mRNA-1010.3

mRNA-1010.3 is an investigational mRNA-based influenza vaccine candidate developed as part of Moderna's seasonal flu vaccine program. It is a variant of the broader mRNA-1010 series, which targets multiple influenza virus strains by encoding hemagglutinin antigens from circulating A and B lineages, including H1N1, H3N2, B/Yamagata, and B/Victoria[1][5][8]. The mechanism of action involves delivering synthetic messenger RNA encapsulated in lipid nanoparticles to host cells; these cells then produce viral antigens that stimulate an immune response against influenza viruses[2][3]. The primary indication for this drug is the prevention of seasonal influenza infection.